Catalytic method and apparatus



March 3l, 1953 w. F. RoLLMAN CATALYTIC METHOD AND APPARATUS 3 Sheets-Shea?l l Filed Sept. 24, 1946 r A@ n n, 5 n a .m d 2 F n. e n.. a wv dttormeg March 3l, 1953 w. F. RoLLMAN 2,6335477 CATALYTIC METHOD AND APPARATUS Filed sept. 24, 194e 5 Sheets-Sheet 2 C-a Zier F QoZZman Saverzbor EDSMGtbov-rze March 3l, 1953 w. F. ROLLMAN 2,633,477

CATALYTIC METHOD AND APPARATUS Filed Sept. 24, 1946 5 Sheets-Sheet 3 'F1 cih-3 Inf-alter Qozzmdn. Unvenbcrf bborjne Patented Mar. 31, 1953 CATALYTICMETHOD AND API-RATUS Walter F.Rollman, Cranford, N. J., assigner. to

Standard Oil. Development Company, a corporation of Delaware.

Application' September 24, 1946;.SerialNo. 698,948.

1.1 Claims. Cl.. 26o- 687) oxygenated organici compoundsV from carbony monoxideandr hydrogen, dehydrogenation. of. unsaturated hydrocarbonssuch aszalkenes or arylalkanes and various other reactions;

Inra-preferred embodiment ythe apparatus comprises. a hollow; cylinder. or a metallicl drum coated on its outside with acatalyst and rotated by mechanical means abouta central horizontal axiswithinra'second; fixed cylinder or housing.

Means'. are provided. for. introducing. reactant.

vapors-,stripping gases, regeneratingy gases, and the likethrough the-l outer fixed. cylinder into spaces betweenthefixed cylinder.` and the inner rotating one. These spaces are annular sectors of limited width, and thevarious vapor streams arermadev to follow a definite course byl means of suitable bailiesand sealing.V gases such asfsteam. Therotatingcylinder. carrying .the catalyst' coating.. onpits. outer.' surface is provided; with.: means for supplying. a heat exchangeI medium to. its;

interior.` Theouter'cylinder or housing isprovided with outletsy for: uid` products'.`

Reaction is accomplished in the apparatusbyl passing reactant vapors from -afeed entrance in the housing' through a portion of` the annulus between the outer surfaceY of the rotating drum and; the. housingito a. vapor product outlet in the housing. This: portion of: the .annulus serves as areactionv zone. The. reactant. vapors.v and their products4 areA prevented from owing' past' the reaction zone intoy another sector of.. the annulus. surrounding .the rotating` drum by having a smaller clearance between the rotating. drum andV they interior wall ofV thez housing' to serve. as ybaiiie sections inareas adjacent the reaction zone` andY furthermore by introducing, a-

sealingv gas into these baille sections..

In exothermic reactions, the heat of reaction.

is removed .bya .cooling medium inside thedrum, preferably throughform-ation of. steam produced from water. sprayedV on-.the .inside surface. of the drum.- The. rotating .motiono the. drum. aids in Y.

2. preventingl hot spot formation, thus insuring.' uniformity of temperature in the reaction zone.

The principles. involved in the operation. of the'. apparatus have been. provedto be important in the satisfactory control of reactions requiring` close control of reaction conditions and contact time. For example,A it hasbeen. shown that in order toobtainmaximumyieldsof phthalic anhydride by partial oxidationof suitable aromatic hydrocarbon vapors, such. as vapors ol naphthalene, ortho-xylene, or o-toluicAv acid, a. close.. uniform control of the. reaction. temperature. is. required withshort contact times,r such as. afew hundredths of..a.second,.and a very limited cat;- alyst area. is sufficient. The revolving catalyst surface technique is considered the best devised for precision' controlof contact time with uniform reaction temperature and, moreover. for rapid -andcomplete separation of: reactionv prod.- uctsfrom. the catalyst: with a minimum loss of. time and energyY in: bringing back the catalyst into. the reaction zone; Likewise, noexcesscat-ralyst beyondthat actually necessary for the re.- action. is required.

Therformand construction of a'rotating-drum' reactor suitable for 'application of the technique to the oxidation of naphthalene vapor to phthalic anhydridev is indicated in the accompanying drawing. In the drawing:

Figure. 1 shows diagr-ammatically a vertical cross-section of the rotating drum reactor; Fig'- ure 2 shows a cross-section of the'reactor taken at II-II; Figure Sshows a cross-section ofthe reactor taken at III-III through Figure l; Figure 4 shows a central vertical cross-section perpendicular to the horizontal axis similar tolig` ure 2 but with the reactor modied to provide aregeneration zone in the annulus between the housing and the rotating drumV opposite the re- Figs. 2` and 4 are on a reduced axis 2. Theexternal surface 3 of drum! is coated.

with the catalytic agente. g.,y vanadium oxide in the productionof .phthalic anhydride. It is vfeas-- ible to prepare vanadium oxidecoatings on variings can be made quite uniformthin andy tenacious. Ithas likewise been shown that the. ac-

tivity of these. coatings. in. vapor phase. partial` oxidation reactionis equivalent. to that. ofcon'- ous metallic or refr-actorysurfaces and thesecoat'- ventional partial oxidation catalysts employed in a xed bed or with a fluid catalyst technique.

The drum I holds the thin catalytic surface coating around its outer periphery in the form of a middle section band corresponding approximately in width to the width of a groove in the concave inner surface of the housing. Groove 5 is the annular sector which serves as the reaction zone, wherein reactant vapors from a feed inlet port 6 ow and contact with the revolving catalytic surface until they reach the outlet port 7. The reactant vapors form a thin, broad stream which intimately contacts with the arc of revolving catalytic surface of drum I in the reaction zone.

Both the inlet port 6 and outlet port 'l in the housing 8 are in the form of slots coextensive with the width of groove 5 and are located at the opposite circumferential ends of groove 5. Feed inlet pipe 9 is fastened or sealed to the housing 8 over an opening to the inlet port slot 6 for passage of reactant vapor thereto. Similarly, product outlet pipe I8 is fastened or sealed to housing l over an opening to the outlet port 'I for withdrawal of the vapor product from the reaction zone.

Between the inlet and outlet ends of the reaction zone Fig. 2 which occupies the space in groove 5, the housing wall projects lengthwise closer to the outer surface of the revolving drum, thereby forming a baiile II with a minimum clearance I2 between its inner concave surface and the outer surface of the revolving drum passing adjacent thereto. Thereis only a slight tendency for vapor to pass from the reaction zone groove 5 through the small space of this minimum clsarance. A relatively narrow milled slot I3 in the concave surface of the baie II serves as a passage for steam or sealing gas which tends to force its way into the minimum clearance space and thus substantially prevent any flow of reactantvapor or vapor product through this space. The groove I3 extends laterally in the baie projection of housing 8 and is coextensive with the length of the rotating drum I. This groove has an inlet I4 for the steam or sealing gas at the end of the drum.

The disk-shaped ends I5 and I6 of the drum IV have perforations II which act as iiuid outlets and the drum end I5 is centrally attached to a drive Ashaft I8 which is concentric to the horizontal axis of the rotating drum. The drive shaft I8 isrevolved Within a journal opening I9 in the end 20 of housing 8 and a suitable stuirlng box arrangement, not shown in detail, is provided for preventing escape of fluid from the interior of the housing through the journal. The disk-shaped end 28 is secured to flanges ZI of housing 8 by bolts 22 and an intervening packing 23 serves to prevent escape of fluid between the enclosure of 20 and the housing body 8. e e

The perforated disk end I6 of revolving drum I is centrally fastened to a tube 24 which is closed at its innermost end 25 and has laterally spaced small outlet holes 26 for emitting and distributing a heat exchange medium (which is cooling water) to the inside surfaces of the drum. The tube 24 projects outwardly from the rotating drum I into a journal 2, which is centrally located in the disk-shaped enclosure 28 for the housing body 8. This outward projection of tube 24 serves as a shaft opposite the drive shaft and' is open to inflow of heat exchange medium or cooling water from pipe 29 which is coaxially attached to the hub-shaped portion 30 of disk 28. The hubshaped portion 30 which provides the journal 21 for the bearing of tube 24 is provided with a stuffing box arrangement, not shown in detail, to prevent escape of fluid from the interior of the housing 8. The disk 28 is secured to ange ends 3l of housing 8 by bolts 32 which compress the intervening packing 33 against the flange 3| for preventing escape of fluid. A packing ring 44 around each end of the drum prevents leakage of vapors between the reaction zone and the end ofthe drum.

During e operation a heat exchange medium, such as cooling water, flows into tube 2li from pipe inlet 2S and is sprayed through holes 2S in tube 24 against the interior wall surfaces of the rotating drum. It is in order for water to be employed directly as the cooling medium and the quantity of water supplied will be a function of the drum. temperature and pressure maintained within the drum as well as evolved l:heat of reaction. Steam formed in the revolving drum I flows out through perforations II at the ends of the drum and is withdrawn under controlled pressure through the steam outlet pipe Sli attached to the housing end 28. A portion of the steam which leaves the 1nterior of the revolving drum I flows into a milled slot I3 indicated in Figure 3 to act as sealing gas at the surface of the baiiie II. The direction and velocity of the rotating drum can be set with respect to the flow rate of the reactant vapors entering the reaction zone 5 from the inlet port 6 to obtain the desired reaction contact time as the vapor flows through the reaction zone 5 to the outlet port Considering that the drum is rotated in a clockwise direction as .indicated in Figure 2, when the catalytic surface of the drum passes the outlet port 'I and enters the annular space of minimum clearance adjacent the baffle II, it carries along a negligible amount of vapor product and is, furthermore, stripped of vapor product by steam or sealing gas which tends to be forced in a counterclockwise direction toward the outlet port l. A portion of the'sealing gas travels through the minimum clearance in a clockwise direction toward the inlet port 6 and prevents the incoming reactant vapors from entering the minimum clearance space.

In Figures 1, 2, and 3, the total annular space encompassing the revolving drum I is divided into two sections, namely, the reaction zone 5 and the sealing zone in the minimum clearance space I2. This type of construction is suitable in a process which does not require regeneration of the catalyst coating in a zone separate from the reaction zone. For instance, in the production of phthalic anhydride from a suitable aromatic hydrocarbon the reactant vapor enters the reaction zone 5 from inlet port 6 with admixed oxygen-containing gas in proper proportions for the partial oxidation and the vapor product leaves the reaction zone 5 through the outlet port 'I with. excess oxygen. The revolving catalyst surface moving away from the reaction zone is then immediately stripped of any a'dsorbed vapor product by the flow of sealing gas in contact with the surface.

Since the revolving motion of the drum in conjunction with an eicient cooling means minimizes hot spot formation, and since the catalyst can be very quickly transferred from one phase of operation to another in the revolving drum apparatus, the catalyst may be used as an oxygen carrier with precision control of the reaction together with the advantage of avoiding dilutionofthe reactant vapor withoxidizingreagent. f'

aussagen Figure 4 illustrates a simple modiflcationofftlie apparatus for an operation wherein the catalyst is used as an oxygen carrier. In thismodication the annulus around the entire circumference of the drum is divided into four sections, namely, the reaction zone 5, an opposite regeneration zone 35, and two sealing sections between' the ends' of' the reaction zone in the regenerationfzone. Like the reaction zone 5, the regeneration-zone 35 isV the space in a groove or recess withinV the inner wall of the housing 8. The regenerationA zone- 35 has the same breadth as the reaction zone 5. It begins at an inlet port 36 for regenerating gas, such as air, and terminates at an outlet port-`31 where regeneration gas is vented from the housing. The ports 36 and 31, like the ports 6 andi." are in the form of narrow slots coextensive with the width of the zone for prompt distribution and f removal of the regeneration gas. The slots 36 and 31 have a central opening to the exterior wall of the housing 8 and communicate with inlet and outlet lines 38 and 39, respectively. whichA are sealed to the housing 8. With the modified form of housing as shown in. Figurel 4, the. reactantvapor enters the reaction zone. from inlet port 6 to contact with the revolving, surface as it passes zone 5. The-vapor product leaves the reaction zonev 5 through outlet port I and the revolving catalyst surfacemoves from the reaction zone into a minimum clearance space 40 between the baffle 4I and the catalyst surface of the rotating drum I. A sealing gas, vsuch as steam, is forced clockwise and counter-clockwise through the minimum clearance space from thermilled slot` 42 which, like the already-explained.groove I3, is a communicating passage forv a part of the steam formed fromthe cooling water inside the revolving drum. WhenV thel revolving catalyst surface entersthe regeneration zone V35V it is contacted with regeneration air entering from inlet port 38. On passing from the: regeneration zone 35 into the minimum clearance space I2 the oxidized or regenerated catalyst surface is contacted with the` sealing gas or steam entering-from slot I3. Thereafter, the regenerated catalyst surface revolves into reaction zone 5 to begin a new cycle.

Av number of advantages of operation with the revolving catalyst surface. as compared to con' ventional methods of operation, and the manner in which observed experimental data apply tothe operation, will be apparent-from the following discussion of operations in which a regeneration zone is omitted and in which the` regeneration zone is used. In carrying out the. partial oxidation of naphthalene vapor to phthalic anhydride with admixed air using an apparatus illustrated in i Figures 1; "2; and 3i a: mixture; cti: 2. mole per cent naphthalenefvaporin air is admitted to the reaction zone and no regeneration zone is required. Conventional ilxed bed practice is limited to. afeedconcentration of about 0.8 mole per cent of naphthalene vapor in air and the higher concentration of thereactantvapor'in air'utilizable with the revolving catalyst surface technique reduces fthecost of the process materially. This reduction in cost is indicated by the fact thatthe air demand and-fixed gas productionarelowered inl using a higher feed concentrationV and improved control cil reaction conditions.

With a catalyst-coated'fdrum 10ft. long" and 3:- ft. indiameter revolvingatl 'aspeed of 120 R. P. M. ,and with a reaction space fa in. wide in theannulus between thedrum and* the-jacket. thereactantvapor feed can'be supplied Vata'ratev equivalent; to a contact time oft/100. of a second and give such a reactor a capacity of about 1'5ns per day of phthalic` anhydrideat% selectivity. Since conditions in the reaction zone are quite uniform, a 90% selectivity is readily obtainable. Theremoval of heat from the drum is nolimitation and since the heat is yremovedat ahigh level it may loe/obtained directly inI theform of high pressure. steam if desired.

When the catalyst on` the surfaceof the1drum isemployed as. an oxygen carrier for the process. no molecular oxygen is required in the reaction zone,.and the oxygenis supplied to the carrier in the regeneration zone.v AIi'or instance, naphthalene vapor is introducedA into the reaction zone of theannulusand reacts therein. with oxygen contained inthe-vanadium oxideon the re volving surfaceofl the rotating drum. Thevanadium oxide `thus reduced` is reoxidized with .air in the: separate regeneration.. section of the annulus. An advantage-.of this technique4 resides in the reduction of the ixedgas that must be handled in a recovery system. For a drum rotating ataspeed of- 285 R. P. M., it is indicated that, avanadiuxn oxidecoatingthickne'ss of less than 0.02.mm. isfsufiicientto supply'sufcient oxygen for the transferof oxygenrfrom the catalyst tothe napthalene vapor.

Inrthe following' table are summarized recommended conditions .for partial .oxidationof naphthalenerusingthe revolving -catalyst surface tech,- nique, first with the reactant naphthalene vapor in admixture with air (A) and secondly, with no admixture of a-ir in the reaction zone but regeneration of the catalyst by air in a-regeneration zone (B). In the third column of the table data are listed with regard to a vconventional fixed bed operationfor comparison. i

Mettod of partially oxidizing hydrocarbons [Production of phthalic anhydride] A Bv C Conv. Fixed Case Operation Catalyst Rotatingv Drum-@Vanadium Bed-Vana- Oxide .on Metallic Surface dium Oxide on Corundum Coolant; Water Salt or Mercuryj Catalytic Suriace'Exposed to Air and Hydro- SinzailtaiieouslyV .Alternatelyv Simultaneously.

car on. Naphthtalene in Air, mole Percent 2 100 0.8 Air Demand, cu. it. e 145 145 368. selectivity to P. A., Percen 90Y 90 76. ixed Gas Produced, cu ft /lb P A- 130 7 410. Capacity of Unit, tons P A /Day-- l5 15 l1 Maximum engthof D ft 10 10v Diameter of Drum, K 3 3- peed of Drum, R; P; M 2 285 Method; of partially oxidizing hydrocarbons-Continued [Production of phthalic anhydride] A B C Conv. Fixed Case Operation Catalyst Rotating Drum-Vanadium Bed-Vans- Oxide on Metallic Surface dium Oxide on Corundum Coolant Water Salt or Mercury Annulus Drum to Jacket, in l@ 26 Arc of Drum in Reaction Zone, im...` 100. 20. Arc of Drum in Regeneration Zone, in 90. Contact Time of Vapors in Reaction Zone, sec 0.02 0.04 Contact Time of Drum in Reaction Zone, sec. 0.44 0.04 Contact Time of Drum in Regeneration Zone, sec 0.17 Catalyst Surface Loading, lbs. naphJsq.

ft./hr.. 13.3 13.3 Catalyst Temperature, oE 1,050. 1,050. Heat Absorbed by Coolant, B. t. u./sq'. infin- 3,750. 5,630. (Assumed fraction of drum surface eiect-ive for cooling) M Pressure in 'Reaction Zone, p. s. i. g 30. 30. Required Thickness Effective V. Oxide Film,

For other types of reactions, as, for example,

hydrocarbon synthesis by reaction of carbon mon- Oxide with hydrogen, dehydrogenation of butenes to butadiene, dehydrogenaticn of ethylbenzene to vinyl benzene, the catalyst coatings on the rotating drum are to contain suitable -catalytic ingredients specific to these reactions, as, for example, iron oxide and suitable stabilizers and promoters, such as alumina and potassium oxide. These reactions are also accomplished with a very short contact time land in `reaction such as the synthesis of hydrocarbons the catalyst is quickly regenerated in a separate regeneration zone. In the hydrocarbondehydrogenation reactions the reactant vapors areadmixed with steam on entering' the reaction zone and do not require regeneration of the catalyst. v Numerous modifications and other applications of the described method and apparatus suggest themselves. For example, the length of the drum and the dimensions of the catalyst bed for a given capacity may be changed. The drum may be changed in form to a series of coaxial and hollow disks with catalyst on the outer surfaces of the disks. The technique may also be adapted to endothermic reactions by supplying a heating medium to the internal surface of the revolving drum instead of a cooling medium. The revolving drum surface technique in effect gives results comparable to the results obtainable with the most advanced moving fluid catalyst technique but without problems incidental to the fluid catalyst technique such as catalyst attrition and difficulties of control.

I claim:

l. A method of accomplishing a catalytic reaction of a reactant vapor, which comprises rotating a. cylindrical catalyst coating about a central axis, contactinguthe Abreadth of aunifprmly thin, broad stream of reactant vapor flowing through a reaction zone of uniform cross-section with an outer surface of said coating passing by said zone Vto accomplish thev reaction with non-turbulent flow, stripping reaction product vapor from a portion of the coating revolved past the reaction zone by contact with a stripping gas that acts as a gas seal for the reaction zone, and supplying a fluid to a zone surrounded by the cylindrical catalyst coating for indirect heat exchange between said :duid and the coating.

2. A method of carrying out a catalytic reaction of a reactant vapor, which comprises rotating a cylindrical catalyst coating about its central longitudinal axis, flowing a uniformly thin, broad stream of reactant vapor through a reaction zone sector of an annulus space surrounding the cylindrical catalyst coating, the breadth of the vapor stream being that of the catalyst coating, to accomplish the reaction with non-turbulent ow passing a sealing gas into a stripping sector ofthe annulus space adjacent the reaction zone sector, and passing a regenerating gas into a regeneration sector of the annulus space, said regeneration sector being separated from the reaction sector by said stripping sector.

3. The method of effecting controlled contact of a gaseous reactant with a revolving catalyst surface of cylindrical contour, which comprises spreading the gaseous reactant into a thin, broad stream as it is introduced into a reaction zone between said cylindrical catalyst surface and a concave cylindrical surface spaced therefrom, maintaining said gaseous stream uniformly thin in its dimension between the catalyst surface and said concave surface while a broad 'side of said stream is contacted with the catalyst surface moving along with the stream, and withdrawing' the resulting product stream of the gaseous reactant as a thin, broad stream where contact of the stream with the cylindrical catalyst surface is terminated.

4. The method of catalytically reacting a, compound in vapor phase for a controlled short contact period, which comprises passing vapor of a reactant compound into an annular reaction zone, flowing said vapor in a continuous stream through said reaction zone to accomplish the reaction with non-turbulent ow, contacting the vapor in the reaction zone with a revolving catalyst coating of -cylindrical contour for a controlled short period, stripping Vapor from said catalyst coating as it moves from the reaction zone to a gas sealing zone, said sealing zone being a narrow uniform clearance between the revolving cylindrical catalyst coating and an adjacent stationary wall surface concave with respect to the coating to prevent passage of gas from the reaction zone, and revolving the stripped catalyst coating into contact with the stream of reactant vapor flowing through the reaction zone.

5. The method of catalytically reacting a vapor reactant for a controlled short contact period, which comprises flowing the reactant vapor in a continuous nonturbulent stream through an annularreaction zone of uniform cross-sectional area `between the revolving cylindrical catalyst surface and a stationary surface spaced therefrom and concave thereto, contacting the vapor stream flowing in .thereaction zone with the revolving catalyst coating for. a controlled short period, stripping vapor,.from,the. coating as it passes from the vreactionzone to a gas sealing zone where the cylindricafcatalyst coating has a narrowlclearance from'an adjacent stationary,

surface concave surface' topreVent vapor ow from the reaction zone to the sealing zone, passing an inert gas into said gas sealing zone, cooling the cylindrical coating by conducting heat therefrom through a hollow cylindrical base supporting the coating to a cooling medium inside the hollow cylindrical base, and revolving the stripped, cooled coating into contact with a reactant vapor stream passing through the reaction zone.

6. The method of catalytically reacting a reactant vapor, which comprises flowing a continuous non-turbulent stream of the reactant vapor through a reaction zone between a revolving cylindrical catalyst surface and a stationary cylindrical surface concave thereto, contacting the reactant vapor in said reaction zone with the revolving catalyst surface, steam stripping vapor products from the catalyst surface as it revolves past the reaction zone to a gas-sealing zone in a uniform narrow clearance between the catalyst surface and a stationary surface, passing steam into said sealing zone under pressure to act as a sealing gas and serve in stripping vapor from the catalyst surface moving into the sealing Zone, regenerating the catalyst surface by contact with oxygen as it revolves from the gas sealing zone into a regeneration zone supplied with oxygen, cooling the revolving catalyst surface by conducting heat therefrom through a hollow cylindrical base supporting the catalyst to water sprayed within said hollow base, and revolving the catalyst surface from the regeneration zone through another gas sealing Zone into contact with a stream of reactant vapor flowing through said reaction zone.

7. The method of partially oxidizing an organic reactant vapor, which comp-rises contacting a uniformly thin, broad, non-turbulent stream of the reactant vapor with an outer surface of a revolving catalyst coating of cylindrical contour supported on a revolving cylindrical base during part of its cycle of revolution, stripping reaction vapor products from the revolving catalyst coating as it moves out of contact with said feed stream of reactant vapor by revolving into a gassealing zone through which the reactant vapors and its products are barred from passing, spraying cooling water into the revolving hollow base member to remove heat from the catalyst coating, and withdrawing steam evolved from the cooling water in the interior of said rotating cylinder base.

8. An apparatus for catalytic vapor phase reactions, comprising a housing, a hollow cylindrical member rotatably mounted in the housing, an exterior catalytic surface of cylindrical contour on said hollow member spaced from interior walls of the housing, a uid inlet passage through the housing for introducing reactant vapor into aV reaction zone space of uniform cross-section between the catalytic surface and an interior wall of the housing, a fluid outlet passage through the housing for removing reaction vapor products from said reaction zone space, a baille projecting inwardly from the housing to form a small inlet passage through the baffle for introducinga sealing gas into said small clearance space.

9. An apparatus'for'catalytic vapor phase reactions, comprising a housing. having interior.'v

walliof cylindricaLcontouna drum rotatably mounted in the housing, an exterior cylindrical catalytic surface coating on said drum separated from the interior wall of the housing by an annular space, said annular space being a reaction zone of uniform cross-section over a substantial arc of the cylindrical coating, a fluid inlet slot in the housing for flowing reactant vapor as a thin, broad stream through the reaction zone at one end of said arc, a fluid outlet slot in the housing near the other end of said arc, a baille projecting inwardly from the housing at the other end of said arc with a small clearance space from the cylindrical coating a slot in the baille for passing a thin, broad stream of ribbon-like form of sealing gas into said small clearance space laterally to the cylindrical coating, means for introducing a cooling fluid into the interior of the drum, and a gas flow passage from the interior of the drum to the slot in the baille, the breadth of said streams of reactant vapor and sealing gas being coextensive with the lateral width of the catalyst coating.

10. An apparatus for catalytic vapor phase reactions comprising a housing having interior walls of cylindrical contour, a drum rotatably mounted in the housing, an exterior cylindrical catalytic surface coating on said drum separated from concentric cylindrical interior walls of the housing by annular space sectors, one of these sectors being a reaction zone of uniform cross-section over a substantial arc of the coating, another of the sectors being a regeneration zone, each zone having a uid inlet and fluid outlet passage at each arc end through the housing radial baffles projecting inwardly from the housing between the arc ends of the zones to small clearance spaces from the coating, a passage for sealing gas in the baiies to said small clearance spaces, a hollow shaft on which the drum is mounted coaxially with its longitudinal axis, a bearing in the housing for supporting the shaft, means for passing a fluid into said hollow shaft and spaced perforations in the hollow shaft for distributing fluid therefrom to the interior of the drum.

11. An apparatus for accomplishing catalytic vapor phase reactions, comprising a housing, a rotatable hollow member rotatably mounted on a shaft in said housing, an exterior catalytic surface of cylindrical contour on said hollow member spaced from interior walls of the housing, a fluid inlet passage for introducing a reactant vapor through the housing into a reaction zone space of uniform cross-section between the catalytic surface and an interior wall of the housing, an outlet passage for reaction vapor products through the housing from said reaction zone space, a baille projecting from the housing to a small clearance with the catalytic surface of the rotating member to block reaction vapor products from circulating past the reaction zone space, and a sealing gas inlet through the baille Number into said small clearance space. 1,724,982 WALTER F. ROLLMAN. 2,081,272 2,120,538 REFERENCES CITED 5 2,180,353 The following references are of record in the 275,920 le of this patent: 2,373,008

UNITED STATES PATENTS Number Name Date 10 Number 1,678,778 Harter July 31, 1928 532,481

Name Date Trumble Aug. 20, 1929 Foster May 25, 1937 Andrews June 14, 1938 Foster Nov. 21, 1939 Pelzer et al Mar. 10, 1942 Becker Apr. 3, 1945 FOREIGN PATENTS Country Date Great Britain Jan. 24, 1941 

1. A METHOD OF ACCOMPLISHING A CATALYST REACTION OF A REACTANT VAPOR, WHICH COMPRISES ROTATING A CYLINDRICAL CATALYST COATING ABOUT A CENTRAL AXIS, CONTACTING THE BREADTH OF A UNIFORMLY THIN, BROAD STREAM OF REACTANT VAPOR FLOWING THROUGH A REACTION ZONE OF UNIFORM CROSS-SECTION WITH AN OUTER SURFACE OF SAID COATING PASSING BY SAID ZONE TO ACCOMPLISH THE REACTION WITH NON-TURBULENT FLOW, STRIPPING REACTION PRODUCT VAPOR FROM A PORTION OF THE COATING REVOLVED PAST THE REACTION ZONE BY CONTACT WITH A STRIPPING GAS THAT ACTS AS A GAS SEAL FOR THE REACTION ZONE, AND SUPPLYING A FLUID TO A ZONE SURROUNDED BY THE CYLINDRICAL CATA- 